END-POINT ENERGY IN THE MOLECULAR BETA-SPECTRUM, ATOMIC MASS-DEFECT, AND THE NEGATIVE M(NU(E))(2) PUZZLE

We present the discussion of the modem state of m(nu) measurements on tritium sources. In all experimental studies of the neutrino rest mass , the beta sources have a molecular structure. The peculiarities of th e beta decay in molecules and the connection between the extrapolated endpoint energy, E-0, and the atomic mass defect are analysed. The pos sible reasons for the negative m(nu)(2) puzzle are discussed. We propo se a new strategy of fitting parameters which can help to understand t he origin of negative m(nu)(2) values.